| Flow patterns and velocity distributions in the human vertebrobasilar arterial system. Laboratory investigation. | |
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MedLine Citation:
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PMID: 20136394 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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OBJECT: The authors conducted a study to elucidate the relationship between the flow patterns and the formation of aneurysms at the bifurcation of the basilar artery (BA). METHODS: Six isolated, transparent vertebrobasilar arterial systems were prepared from humans postmortem, and flow patterns and velocity distributions were studied in detail using flow visualization and cinemicrographic techniques. RESULTS: The authors found that if the diameters of 2 vertebral arteries (VAs) were nearly equal and they formed a symmetrical inverted Y-shaped junction with the BA, the BA flow was also symmetrical. The fluid elements that flowed into the BA from 2 VAs traveled almost parallel to the vessel wall of the BA without mixing with each other, and then they flowed out through ipsilateral superior cerebellar and posterior cerebral arteries. In contrast to this, if the diameters of 2 VAs were very different or the BA was badly bent, the BA flow was disturbed as a result of the formation of swirling and secondary flows. The approaching velocity profile at the BA's terminal bifurcation was flattened if the inverted Y-junction was symmetrical, and it was sharpened if the junction was asymmetrical. Thus, in the latter case, fluid elements impinged on the vessel wall around the flow divider of the bifurcation with much larger velocities and, hence, larger kinetic energy, compared with the case of a symmetrical inverted Y-junction, exerting high fluid pressures, wall shear stresses, and wall tensions on the vessel wall there. CONCLUSIONS: The symmetrical structure of the inverted Y-junction in a normal vertebrobasilar arterial system provides a flattened approaching velocity profile at the terminal bifurcation of the BA, lowering the hemodynamic stresses (pressure, tension, and shear stress) exerted on the wall of the bifurcation. This may account for the relatively low incidence of aneurysm formation at this site. |
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Authors:
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Nobuaki Kobayashi; Takeshi Karino |
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Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural |
Journal Detail:
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Title: Journal of neurosurgery Volume: 113 ISSN: 1933-0693 ISO Abbreviation: J. Neurosurg. Publication Date: 2010 Oct |
Date Detail:
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Created Date: 2010-10-04 Completed Date: 2010-10-28 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 0253357 Medline TA: J Neurosurg Country: United States |
Other Details:
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Languages: eng Pagination: 810-9 Citation Subset: AIM; IM |
Affiliation:
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Department of Neurosurgery, Sapporo Kita Neurosurgical Clinic, Sapporo, Japan. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Aged Basilar Artery / anatomy & histology*, physiology* Blood Flow Velocity / physiology* Cadaver Cerebrovascular Circulation / physiology* Hemodynamics / physiology Humans Intracranial Aneurysm / pathology, physiopathology Kinetics Pulse Vertebral Artery / anatomy & histology*, physiology* |
| Grant Support | |
ID/Acronym/Agency:
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HL-29502/HL/NHLBI NIH HHS |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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